CN104755759B - Variable displacement swash plate compressor - Google Patents

Abstract

The variable capacity swash plate compressor of the present invention includes: a housing formed with a suction chamber, a discharge chamber, a swash plate chamber, and a cylinder bore; a drive shaft rotatably supported by the housing; and a swash plate. , which can rotate in the swash plate chamber by the rotation of the drive shaft; an actuator, which can change the inclination angle of the swash plate; and a control mechanism, which controls the actuator. A pressure adjustment chamber is formed in the housing. The actuator has a fixed body, a movable body capable of changing the inclination angle of the swash plate, and a control pressure chamber for moving the movable body. The control mechanism has a control passage that communicates the discharge chamber, the pressure adjustment chamber, and the control pressure chamber, and a control valve that adjusts the opening of the control passage to change the pressure in the control pressure chamber so that the movable body can move. The refrigerant in the discharge chamber flows into the control pressure chamber via the pressure adjustment chamber. The pressure adjustment chamber functions as a muffler that reduces pulsation of the refrigerant.

Description

Variable capacity swash plate compressor

technical field

The present invention relates to variable capacity swash plate compressors.

Background technique

Patent Document 1 discloses a conventional variable capacity swash plate compressor (hereinafter referred to as a compressor). In this compressor, a casing is formed by a front casing, a cylinder block, and a rear casing. A suction chamber and a discharge chamber are respectively formed in the front case and the rear case. In addition, a control pressure chamber is formed in the rear case.

A swash plate chamber, a plurality of cylinder bores, and a main shaft through hole are formed in the cylinder block. Each cylinder bore is comprised of the 1st cylinder bore formed in the rear side of a cylinder block, and the 2nd cylinder bore formed in the front side of a cylinder block. A main shaft through hole is formed on the rear side of the cylinder block, and communicates with the swash plate chamber and the control pressure chamber.

The drive shaft is inserted through the housing and is rotatably supported within the cylinder body. A swash plate rotatable by rotation of the drive shaft is provided in the swash plate chamber. A link mechanism that allows the inclination angle of the swash plate to be changed is provided between the drive shaft and the swash plate. Here, the inclination angle refers to the angle formed by the swash plate relative to the direction perpendicular to the rotation axis of the drive shaft.

In addition, pistons are reciprocally housed in the respective cylinder bores. Specifically, each piston has a first head that reciprocates in the first cylinder bore, and a second head that reciprocates in the second cylinder bore. Thus, in this compressor, the first compression chamber is formed by the first cylinder bore and the first head, and the second compression chamber is formed by the second cylinder bore and the second head. The conversion mechanism reciprocates each piston in the cylinder bore with a stroke corresponding to the inclination angle by the rotation of the swash plate. In addition, the actuator is capable of changing the angle of inclination, and the control mechanism controls the actuator.

The actuator is arranged in the swash plate chamber on the first cylinder bore side with the swash plate as a reference. This actuator is composed of a non-rotating movable body, a movable body, a thrust bearing, and the above-mentioned control pressure chamber. The non-rotational movable body is disposed in the main shaft through hole so as not to rotate integrally with the drive shaft, and covers the rear end of the drive shaft. The non-rotational movable body supports the rear end portion of the drive shaft so as to be rotatable and slidable via the inner peripheral surface. In addition, the outer peripheral surface of the non-rotating movable body slides in the direction of the rotation axis in the main shaft through hole, thereby being able to move in the front and back directions in the main shaft through hole. On the other hand, the non-rotational movable body does not slide around the rotational axis of the non-rotational movable body. The movable body is connected to the swash plate, and can move in a direction along the rotation axis. Thrust bearings are provided between the non-rotating movable body and the movable body.

By arranging the non-rotating movable body in the main shaft through hole in this way, the main shaft through hole is divided into a rear end portion communicating with the control pressure chamber and a front end portion not communicating with the control pressure chamber. Furthermore, the rear end portion of the main shaft through hole functions as a part of the control pressure chamber by communicating with the control pressure chamber. In addition, a pressing spring for biasing the non-rotational movable body forward is provided at the rear end portion.

The control mechanism has a control passage and a control valve provided in the control passage. The control passage communicates the control pressure chamber with the discharge chamber. The control valve adjusts the opening degree of the control passage to change the pressure in the control pressure chamber so that the non-rotating movable body and the movable body can move in a direction along the rotation axis.

The link mechanism includes a movable body and a cantilever fixed to the drive shaft. At the rear end portion of the cantilever, a long hole extending in a direction perpendicular to the rotation axis and extending from the radially outer side toward the rotation axis is formed. The swash plate is supported so as to be able to swing around the first swing axis by a pin inserted through the elongated hole at the front thereof. In addition, an elongated hole extending in a direction perpendicular to the rotation axis and extending from the radially outer side toward the rotation axis is also formed at the front end portion of the movable body. The swash plate is supported so as to be able to swing around a second swing axis parallel to the first swing axis by a pin inserted through the elongated hole at its rear end.

In this compressor, the control valve adjusts the opening degree of the control passage, whereby the pressure in the control pressure chamber can be adjusted based on the pressure of the discharged refrigerant in the discharge chamber. Thus, in this compressor, the actuator can change the inclination angle of the swash plate and can change the discharge capacity per revolution of the drive shaft.

Patent Document 1: Japanese Patent Application Laid-Open No. 5-172052

In the above conventional compressor, when the inclination angle of the swash plate is changed, the discharged refrigerant flows directly into the control pressure chamber through the control mechanism. In this compressor, therefore, the actuator is easily affected by the pulsation of the discharged refrigerant. Therefore, in this compressor, the inclination angle is unstable, and it is difficult to operate with an appropriate discharge capacity according to the operating conditions of a vehicle or the like on which it is mounted.

Contents of the invention

An object of the present invention is to provide a variable capacity swash plate compressor capable of operating with an appropriate discharge capacity.

One aspect of the present invention to achieve the above object provides a variable capacity swash plate compressor. A variable capacity swash plate compressor includes: a casing in which a suction chamber, a discharge chamber, a swash plate chamber, and a cylinder bore are formed; a drive shaft rotatably supported by the casing; and a swash plate in which The rotation of the drive shaft can be rotated in the swash plate chamber; the link mechanism, which is arranged between the drive shaft and the swash plate, allows the swash plate to rotate relative to the axis of rotation of the drive shaft The change of the inclination angle in the orthogonal direction; the piston is accommodated in the cylinder bore in a reciprocating manner; a stroke corresponding to the inclination angle, reciprocating in the cylinder bore; an actuator, which can change the inclination angle of the swash plate; and a control mechanism, which controls the actuator, formed in the housing There is a pressure adjustment chamber, and the actuator has: a fixed body fixed to the drive shaft in the swash plate chamber; a movable body arranged on the drive shaft and moving along the drive shaft moving in the direction of the rotation axis, capable of changing the inclination angle of the swash plate; and a control pressure chamber, which is divided by the fixed body and the movable body, changes itself by the pressure of the refrigerant in the discharge chamber. to move the movable body, the control mechanism has: a control passage that communicates the discharge chamber, the pressure adjustment chamber, and the control pressure chamber; and a control valve that adjusts the control The opening of the passage changes the pressure in the control pressure chamber so that the movable body can move, and the refrigerant in the discharge chamber flows into the control pressure chamber through the pressure adjustment chamber. The chamber functions as a muffler that reduces pulsation of the refrigerant.

Description of drawings

Fig. 1 is a cross-sectional view of the compressor of the first embodiment at the maximum capacity.

Fig. 2 is a schematic diagram showing a control mechanism relating to the compressor of the first embodiment.

Fig. 3 is a cross-sectional view of the compressor of the first embodiment at the time of minimum capacity.

Fig. 4 is a cross-sectional view of the compressor of the second embodiment at the time of maximum capacity.

Fig. 5 is a schematic diagram showing a control mechanism related to the compressor of the second embodiment.

Fig. 6 is a cross-sectional view of the compressor of the second embodiment at the time of minimum capacity.

detailed description

Hereinafter, a first embodiment and a second embodiment embodying the present invention will be described with reference to the drawings. The compressor of the first embodiment is a capacity-variable double-head swash plate compressor. On the other hand, the compressor of the second embodiment is a capacity variable single head swash plate compressor. The above-mentioned compressors are all mounted on the vehicle and constitute a refrigeration circuit of the vehicle air conditioner.

(first embodiment)

As shown in FIG. 1 , the compressor of the first embodiment includes: a casing 1, a drive shaft 3, a swash plate 5, a link mechanism 7, a plurality of pistons 9, a pair of shoes 11a, 11b, an actuator 13, and The control mechanism 15 shown in FIG. 2 .

As shown in Figure 1, the casing 1 has: a front casing 17 positioned at the front side of the compressor; a rear casing 19 positioned at the rear side of the compressor; a first casing between the front casing 17 and the rear casing 19; the cylinder block 21 , the second cylinder block 23 ; and the first valve forming plate 39 and the second valve forming plate 41 .

A protrusion 17 a protruding forward is formed on the front case 17 . A shaft seal 25 is arranged in this projection 17a. In addition, a first suction chamber 27 a and a first discharge chamber 29 a are formed in the front housing 17 . The first suction chamber 27 a is located radially inside the front housing 17 . The first discharge chamber 29 a is formed in an annular shape, and is located radially outside the first suction chamber 27 a within the front housing 17 .

In addition, a first front communication passage 18 a is formed in the front case 17 . The front end of the first front communication passage 18 a communicates with the first discharge chamber 29 a , and the rear end of the first front communication passage 18 a opens at the rear end of the front case 17 .

The control mechanism 15 described above is provided on the rear case 19 . In addition, the rear housing 19 is formed with a second suction chamber 27 b, a second discharge chamber 29 b, and a pressure adjustment chamber 31 . The pressure adjustment chamber 31 is located in the central portion of the rear case 19 . The second suction chamber 27 b is formed in an annular shape, and the second suction chamber 27 b is located radially outside of the pressure adjustment chamber 31 in the rear housing 19 . The second discharge chamber 29 b is also formed in an annular shape, and is located radially outside the second suction chamber 27 b within the rear housing 19 . That is, in the rear housing 19, the pressure adjustment chamber 31 is formed radially inward of the second discharge chamber 29b and the second suction chamber 27b. This rear case 19 corresponds to the cover in the present invention.

Here, by forming the pressure adjustment chamber 31 in the rear housing 19 , in this compressor, the pressure adjustment chamber 31 is located at the rear end of the drive shaft 3 .

In addition, a first rear communication path 20 a is formed in the rear cabinet 19 . The first rear communication passage 20 a communicates with the second discharge chamber 29 b at its rear end, and the front end of the first rear communication passage 20 a opens at the front end of the rear cabinet 19 .

A swash plate chamber 33 is formed between the first cylinder block 21 and the second cylinder block 23 . The swash plate chamber 33 is located substantially at the center in the front-rear direction of the casing 1 .

In the first cylinder block 21 , a plurality of first cylinder bores 21 a are arranged at equal angular intervals in the circumferential direction, and are formed in parallel to the rotation axis O of the drive shaft 3 . In addition, a first shaft hole 21 b through which the drive shaft 3 is inserted is formed in the first cylinder block 21 . A first slide bearing 22a is provided in the first shaft hole 21b. In addition, a rolling bearing may be provided instead of the first slide bearing 22a.

In addition, a first recess 21c communicating with the first shaft hole 21b and coaxial with the first shaft hole 21b is formed in the first cylinder block 21 . The first concave portion 21c communicates with the swash plate chamber 33 and becomes a part of the swash plate chamber 33 . The first concave portion 21c is formed in a shape whose diameter decreases stepwise toward the front end. A first thrust bearing 35a is provided at the front end of the first concave portion 21c. In addition, a first connection passage 37a that communicates the swash plate chamber 33 and the first suction chamber 27a is formed in the first cylinder block 21 . In addition, a first stop groove 21e is recessed in the first cylinder block 21, and the first stop groove 21e limits the maximum opening degree of each first suction reed valve 391a described later.

In addition, a second front communication passage 18 b is formed in the first cylinder block 21 . The front end of the second front communication passage 18 b opens at the front end of the first cylinder block 21 , and the rear end of the second front communication passage 18 b opens at the rear end of the first cylinder block 21 .

Like the first cylinder block 21 , a plurality of second cylinder bores 23 a are also formed in the second cylinder block 23 . Each of the second cylinder bores 23a and the corresponding first cylinder bore 21a form a pair front and rear. Each first cylinder bore 21a and each second cylinder bore 23a are formed to have the same diameter.

In addition, a second shaft hole 23 b through which the drive shaft 3 is inserted is formed in the second cylinder block 23 . The second shaft hole 23 b communicates with the pressure adjustment chamber 31 . A second slide bearing 22b is provided in the second shaft hole 23b. In addition, a rolling bearing may be provided instead of the second slide bearing 22b. The above-mentioned first shaft hole 21b and second shaft hole 23b correspond to the shaft hole in the present invention.

Here, in this compressor, the pressure adjustment chamber 31 is formed to have a larger diameter than the first shaft hole 21b and the second shaft hole 23b. Thus, in this compressor, the second cylinder block 23 and the rear housing 19 are joined via the second valve forming plate 41 , whereby the pressure adjustment chamber 31 is in a state of covering the second shaft hole 23 b.

In addition, a second recessed portion 23 c that communicates with the second shaft hole 23 b and is coaxial with the second shaft hole 23 b is formed in the second cylinder block 23 . The second concave portion 23 c also communicates with the swash plate chamber 33 and becomes a part of the swash plate chamber 33 . The second concave portion 23c is formed in a shape whose diameter decreases stepwise toward the rear end. A second thrust bearing 35b is provided at the rear end of the second concave portion 23c. In addition, a second connection path 37 b that communicates the swash plate chamber 33 with the second suction chamber 27 b is formed in the second cylinder block 23 . In addition, the second cylinder block 23 is concavely provided with a second stop groove 23e, and the second stop groove 23e limits the maximum opening of each second suction reed valve 411a described later.

The second cylinder block 23 is formed with a discharge hole 230 , a combined discharge chamber 231 , a third front communication passage 18 c , a second rear communication passage 20 b , and a suction hole 330 . The discharge hole 230 communicates with the combined discharge chamber 231 . The discharge hole 230 and the merged discharge chamber 231 are formed on the front end side of the second cylinder block 23 and are located approximately in the center of the casing 1 in the front-rear direction. The confluence discharge chamber 231 is connected to a condenser (not shown) constituting a pipeline through the discharge hole 230 .

The front end of the third front communication passage 18 c is opened at the front end of the second cylinder block 23 , and the rear end of the third front communication passage 18 c communicates with the confluence discharge chamber 231 . The third front communication passage 18c communicates with the rear end of the second front communication passage 18b by connecting the first cylinder block 21 and the second cylinder block 23 .

The second rear communication passage 20 b communicates with the confluence discharge chamber 231 at its front end, and the rear end of the second rear communication passage 20 b opens at the rear end of the second cylinder block 23 .

The suction hole 330 is formed at a position close to the front end side of the second cylinder block 23 , and is located substantially at the center in the front-rear direction of the housing 1 . The swash plate chamber 33 is connected to an evaporator (not shown) constituting a pipeline through the suction hole 330 .

The first valve forming plate 39 is disposed between the front housing 17 and the first cylinder block 21 . In addition, a second valve forming plate 41 is provided between the rear housing 19 and the second cylinder block 23 .

The first valve forming plate 39 has a first valve plate 390 , a first suction valve plate 391 , a first discharge valve plate 392 , and a first baffle plate 393 . The same number of first suction holes 390 a as the first cylinder bores 21 a are formed in the first valve plate 390 , the first discharge valve plate 392 , and the first baffle plate 393 . In addition, the same number of first discharge holes 390 b as the first cylinder bores 21 a are formed in the first valve plate 390 and the first suction valve plate 391 . In addition, a first suction communication hole 390 c is formed in the first valve plate 390 , the first suction valve plate 391 , the first discharge valve plate 392 , and the first damper 393 . In addition, a first discharge communication hole 390 d is formed in the first valve plate 390 and the first suction valve plate 391 .

Each first cylinder bore 21a communicates with the first suction chamber 27a through the corresponding first suction hole 390a. In addition, each of the first cylinder bores 21a communicates with the first discharge chamber 29a through the corresponding first discharge hole 390b. The first suction chamber 27a and the first connection path 37a communicate with each other through the first suction communication hole 390c. The first front communication passage 18a and the second front communication passage 18b communicate with each other through the first discharge communication hole 390d.

The first suction valve plate 391 is disposed on the rear surface of the first valve plate 390 . The first suction valve plate 391 is formed with a plurality of first suction reed valves 391a that can open and close corresponding first suction holes 390a through elastic deformation. In addition, the first discharge valve plate 392 is disposed on the front surface of the first valve plate 390 . A plurality of first discharge reed valves 392a capable of opening and closing corresponding first discharge holes 390b by elastic deformation are formed on the first discharge valve plate 392 . The first baffle 393 is disposed on the front surface of the first discharge valve plate 392 . The first damper 393 limits the maximum opening of each first discharge reed valve 392a.

The second valve forming plate 41 has a second valve plate 410 , a second suction valve plate 411 , a second discharge valve plate 412 , and a second baffle plate 413 . The same number of second suction holes 410 a as the second cylinder bores 23 a are formed in the second valve plate 410 , the second discharge valve plate 412 , and the second baffle plate 413 . In addition, the same number of second discharge holes 410 b as the second cylinder bores 23 a is formed in the second valve plate 410 and the second suction valve plate 411 . In addition, a second suction communication hole 410 c is formed in the second valve plate 410 , the second suction valve plate 411 , the second discharge valve plate 412 , and the second baffle plate 413 . In addition, a second discharge communication hole 410 d is formed in the second valve plate 410 and the second suction valve plate 411 .

Each second cylinder bore 23a communicates with the second suction chamber 27b through the corresponding second suction hole 410a. In addition, each of the second cylinder bores 23a communicates with the second discharge chamber 29b through the corresponding second discharge hole 410b. The second suction chamber 27b and the second connection path 37b communicate with each other through the second suction communication hole 410c. The first rear communication passage 20a and the second rear communication passage 20b communicate with each other through the second discharge communication hole 410d.

The second suction valve plate 411 is disposed on the front surface of the second valve plate 410 . A plurality of second suction reed valves 411 a that can open and close corresponding second suction holes 410 a by elastic deformation are formed on the second suction valve plate 411 . In addition, the second discharge valve plate 412 is disposed on the rear surface of the second valve plate 410 . A plurality of second discharge reed valves 412 a that can open and close corresponding second discharge holes 410 b by elastic deformation are formed on the second discharge valve plate 412 . The second baffle 413 is disposed on the rear surface of the second discharge valve plate 412 . The second damper 413 limits the maximum opening of each second discharge reed valve 412a.

In this compressor, the first communication passage 18 is formed by the first front communication passage 18a, the first discharge communication hole 390d, the second front communication passage 18b, and the third front communication passage 18c. In addition, the second communication passage 20 is formed by the first rear communication passage 20a, the second discharge communication hole 410d, and the second rear communication passage 20b.

In addition, in this compressor, the first and second suction chambers 27a and 27b and the swash plate chamber 33 communicate with each other through the first and second connection paths 37a and 37b and the first and second suction communication holes 390c and 410c. . Therefore, the pressure in the first and second suction chambers 27a and 27b is substantially equal to the pressure in the swash plate chamber 33 . And, because the low-pressure suction refrigerant through the evaporator flows into the swash plate chamber 33 through the suction hole 330, the respective pressures in the swash plate chamber 33 and in the first and second suction chambers 27a and 27b are higher than the first and second suction chambers 27a and 27b. The pressure in the second discharge chambers 29a, 29b is low pressure.

The drive shaft 3 is comprised of the drive shaft main body 30, the 1st support member 43a, and the 2nd support member 43b. The drive shaft main body 30 extends from the front to the rear of the housing 1, and is inserted from the protrusion 17a to the rear to be inserted into the first and second sliding bearings 22a and 22b. Accordingly, the drive shaft main body 30 is rotatably supported by the casing 1 around the rotation axis O, and the drive shaft 3 is rotatably supported by the casing 1 around the rotation axis O. The front end of the drive shaft main body 30 is located in the protrusion 17 a, and the rear end is located in the pressure adjustment chamber 31 .

In addition, the drive shaft main body 30 is provided with a swash plate 5 , a link mechanism 7 , and an actuator 13 . The above-mentioned swash plate 5 , link mechanism 7 and actuator 13 are respectively arranged in the swash plate chamber 33 .

The first support member 43 a is press-fitted into the front end side of the drive shaft main body 30 . The first support member 43a is rotated around the rotation axis O by the drive shaft 3, thereby sliding in the first slide bearing 22a. Moreover, the flange 430 which abuts on the 1st thrust bearing 35a is formed in this 1st support member 43a, and the attachment part (illustration omitted) which penetrates the 2nd pin 47b mentioned later is formed. Moreover, the front-end|tip of the 1st return spring 44a is fixed to the 1st support member 43a. The first return spring 44 a extends from the first support member 43 a toward the swash plate chamber 33 in a direction along the rotation axis O. As shown in FIG.

The second support member 43 b is press-fitted into the rear end side of the drive shaft main body 30 . The second support member 43b is rotated around the rotation axis O by the drive shaft 3, thereby sliding in the second sliding bearing 22b. Moreover, the flange 431 which abuts on the 2nd thrust bearing 35b is formed in this 2nd support member 43b. This flange 431 is arranged between the second thrust bearing 35 b and the actuator 13 .

The swash plate 5 is formed in an annular flat plate shape and has a front surface 5 a and a rear surface 5 b. The front surface 5 a faces the front of the compressor inside the swash plate chamber 33 . In addition, the rear surface 5 b faces the rear of the compressor inside the swash plate chamber 33 .

The swash plate 5 is fixed to the annular plate 45 . The annular plate 45 is formed in an annular flat plate shape. An insertion hole 45 a is formed in the center portion of the annular plate 45 . The swash plate 5 is attached to the drive shaft 3 by inserting the drive shaft main body 30 into the insertion hole 45 a in the swash plate chamber 33 .

The link mechanism 7 has a cantilever 49 . The boom 49 is arranged in front of the swash plate 5 in the swash plate chamber 33 and is located between the swash plate 5 and the first support member 43a. The cantilever 49 is formed in a substantially L-shape from the front end side toward the rear end side. As shown in FIG. 3 , when the inclination angle of the swash plate 5 with respect to the rotation axis O is at a minimum, the cantilever 49 comes into contact with the flange 430 of the first support member 43 a. Therefore, in this compressor, the inclination angle of the swash plate 5 can be kept at a minimum by the suspension arm 49 . In addition, a weight portion 49 a is formed on the rear end side of the boom 49 . The weight portion 49 a extends over approximately half of the circumference of the actuator 13 . In addition, the shape of the weight part 49a can be changed suitably.

As shown in FIG. 1 , a portion on the rear side of the cantilever 49 is connected to a portion on the first side of the ring plate 45 by a first pin 47 a. Accordingly, the front side portion of the cantilever 49 is supported by the first side portion of the annular plate 45 so as to be able to swing around the first swing axis M1 with the axis of the first pin 47a as the first swing axis M1. Namely swash plate 5. The first swing axis M1 extends in a direction perpendicular to the rotation axis O of the drive shaft 3 .

The front side part of the cantilever 49 is connected to the 1st support member 43a by the 2nd pin 47b. Accordingly, the rear portion of the cantilever 49 is supported by the first support member 43a, which is the drive shaft 3, so as to be able to swing around the second swing axis M2 with the axis of the second pin 47b as the second swing axis M2. The second swing axis M2 extends parallel to the first swing axis M1. The said cantilever 49, the 1st pin 47a, and the 2nd pin 47b correspond to the link mechanism 7 in this invention.

The weight portion 49 a extends toward the side opposite to the second swing axis M2 based on the rear portion of the cantilever 49 , that is, the first swing axis M1 . Therefore, the cantilever 49 is supported by the annular plate 45 by the first pin 47a, so that the weight portion 49a is located on the rear surface of the annular plate 45, that is, behind the rear surface 5b of the swash plate 5, through the groove portion 45b of the annular plate 45. Furthermore, the centrifugal force generated by the rotation of the swash plate 5 around the rotation axis O also acts on the weight portion 49 a on the rear surface 5 b of the swash plate 5 .

In this compressor, the swash plate 5 and the drive shaft 3 are connected to each other via a link mechanism 7 , and the swash plate 5 can rotate together with the drive shaft 3 . In addition, the two ends of the suspension arm 49 respectively swing around the first swing axis M1 and the second swing axis M2, whereby the swash plate 5 can change the inclination angle.

Each piston 9 has a first head portion 9a on the front side and a second head portion 9b on the rear side. Each first head portion 9a is reciprocally accommodated in each first cylinder bore 21a. The first compression chambers 21d are defined in the first cylinder bores 21a by the first heads 9a and the first valve forming plates 39, respectively. Each second head portion 9b is reciprocally accommodated in each second cylinder bore 23a. The second compression chambers 23d are defined in the second cylinder bores 23a by the second heads 9b and the second valve forming plates 41, respectively. However, as mentioned above, since the 1st cylinder bore 21a and the 2nd cylinder bore 23a have the same diameter, the 1st head part 9a and the 2nd head part 9b are formed in the same diameter.

In addition, an engaging portion 9 c is formed at the center of each piston 9 . A pair of hemispherical shoes 11a, 11b are respectively provided in each engaging portion 9c. The rotation of the swash plate 5 is converted into the reciprocating motion of the piston 9 by the above-mentioned shoes 11a, 11b. The shoes 11a, 11b correspond to the conversion mechanism in this invention. In this way, the first head portion 9a and the second head portion 9b can reciprocate in the first cylinder bore 21a and the second cylinder bore 23a at a stroke corresponding to the inclination angle of the swash plate 5 .

Wherein, in this compressor, the stroke of the piston 9 changes with the change of the inclination angle of the swash plate 5, so that the respective top dead center positions of the first head 9a and the second head 9b move. Specifically, as shown in FIG. 1 , when the inclination angle of the swash plate 5 is the maximum and the stroke of the piston 9 is the maximum, the top dead center position of the first head 9 a becomes the position closest to the first valve forming plate 39 . position, the top dead center position of the second head portion 9b is the position closest to the second valve forming plate 41 . On the other hand, as shown in FIG. 3 , as the inclination angle of the swash plate 5 decreases and the stroke of the piston 9 decreases, the top dead center position of the second head portion 9 b gradually moves away from the second valve forming plate 41 . On the other hand, the top dead center position of the first head portion 9 a hardly changes when the stroke of the piston 9 is maximum, and maintains a position close to the first valve forming plate 39 . That is, in this compressor, as the inclination angle of the swash plate 5 decreases, the top dead center position of the second head portion 9b moves more than the top dead center position of the first head portion 9a.

As shown in FIG. 1 , the actuator 13 is arranged in a swash plate chamber 33 . The actuator 13 is located behind the swash plate 5 and can enter into the second concave portion 23c. The actuator 13 has a movable body 13a, a fixed body 13b, and a control pressure chamber 13c. The control pressure chamber 13c is formed between the movable body 13a and the fixed body 13b.

The movable body 13a has a main body portion 130 and a peripheral wall 131 . The main body portion 130 is located behind the movable body 13 a and extends radially in a direction away from the rotation axis O. As shown in FIG. The peripheral wall 131 is continuous with the outer peripheral edge of the main body portion 130 and extends from the front to the rear. In addition, a connection portion 132 is formed at the front end of the peripheral wall 131 . The movable body 13 a has a bottomed cylindrical shape formed by the above-mentioned main body portion 130 , peripheral wall 131 , and connection portion 132 .

The fixed body 13b is formed in a disc shape having substantially the same diameter as the inner diameter of the movable body 13a. A second return spring 44b is disposed between the fixing body 13b and the annular plate 45 . Specifically, the rear end of the second return spring 44 b is fixed to the fixing body 13 b, and the front end of the second return spring 44 b is fixed to the second side portion of the annular plate 45 .

The drive shaft main body 30 is inserted through the movable body 13a and the fixed body 13b. As a result, the movable body 13 a is accommodated in the second concave portion 23 c and is disposed in a state of facing the link mechanism 7 with the swash plate 5 interposed therebetween. On the other hand, the fixed body 13 b is disposed in the movable body 13 a at the rear of the swash plate 5 , and its periphery is surrounded by the peripheral wall 131 . Thus, a control pressure chamber 13c is formed between the movable body 13a and the fixed body 13b. The control pressure chamber 13c is partitioned from the swash plate chamber 33 by the main body portion 130 of the movable body 13a, the peripheral wall 131, and the fixed body 13b.

In addition, the drive shaft 3 , rear housing 19 and second cylinder block 23 define a pressure adjustment chamber 31 and a control pressure chamber 13 c in addition to the main body 130 , peripheral wall 131 , and fixed body 13 b of the movable body 13 a.

In this compressor, the movable body 13 a can rotate together with the drive shaft 3 by being inserted through the drive shaft body 30 , and can move in the direction along the rotation axis O of the drive shaft 3 in the swash plate chamber 33 . On the other hand, the fixed body 13 b is fixed to the drive shaft main body 30 in a state of being inserted through the drive shaft main body 30 . Thereby, the fixed body 13b can only rotate together with the drive shaft 3, and cannot move like the movable body 13a. In this way, when the movable body 13a moves in the direction of the rotation axis O, it relatively moves with respect to the fixed body 13b.

The second side part of the annular plate 45 is connected to the connection part 132 of the movable body 13a via the third pin 47c. Accordingly, the swash plate 5 , which is the second side portion of the annular plate 45 , is supported by the movable body 13 a so as to be swingable around the operating axis M3 with the axis of the third pin 47 c as the operating axis M3 . The action axis M3 extends parallel to the first swing axis M1 and the second swing axis M2. In this way, the movable body 13a is connected to the swash plate 5 . Further, the movable body 13a comes into contact with the flange 431 of the second support member 43b when the inclination angle of the swash plate 5 is at its maximum.

In addition, in the drive shaft main body 30 are formed: an axial path 3a extending from the rear end toward the front in a direction along the rotation axis O, and a shaft path 3a extending radially from the front end of the axial path 3a and on the outer periphery of the drive shaft main body 30 . Surface open path 3b. The rear end of the shaft path 3 a is opened in the pressure adjustment chamber 31 . On the other hand, the path 3b is opened in the control pressure chamber 13c. Thus, the control pressure chamber 13c communicates with the pressure adjustment chamber 31 through the path 3b and the axial path 3a.

A screw portion 3 d is formed at the front end of the drive shaft main body 30 . The drive shaft 3 is connected to an unillustrated pulley or an electromagnetic clutch via the threaded portion 3d.

As shown in FIG. 2 , the control mechanism 15 has a low-pressure passage 15a, a high-pressure passage 15b, a control valve 15c, an orifice 15d, a shaft passage 3a, and a passage 3b. The shaft path 3a and the path path 3b correspond to the variable pressure path in the present invention. In addition, the control passage in the present invention is formed by the above-described low-pressure passage 15a, high-pressure passage 15b, shaft passage 3a, and path passage 3b.

The low-pressure passage 15a is connected to the pressure adjustment chamber 31 and the second suction chamber 27b. The control pressure chamber 13c, the pressure adjustment chamber 31, and the second suction chamber 27b are communicated with each other through the low-pressure passage 15a, the shaft passage 3a, and the passage 3b. The high-pressure passage 15b is connected to the pressure adjustment chamber 31 and the second discharge chamber 29b. The discharged refrigerant in the second discharge chamber 29b flows through the high-pressure passage 15b. The control pressure chamber 13c, the pressure adjustment chamber 31, and the second discharge chamber 29b communicate with each other through the high-pressure passage 15b, the shaft passage 3a, and the passage 3b. In addition, an orifice 15d is provided in the high-pressure passage 15b.

Furthermore, by connecting the second suction chamber 27b, the second discharge chamber 29b, and the pressure adjustment chamber 31 to the control pressure chamber 13c in this way, the pressure adjustment chamber 31 is located between the second suction chamber 27b, the second discharge chamber 29b and the control pressure chamber. Between 13c. In addition, the pressure adjustment chamber 31 is formed as a space having a cross-sectional area larger than any one of the low-pressure passage 15a, the high-pressure passage 15b, the axial passage 3a, and the path 3b.

The control valve 15c is provided in the low-pressure passage 15a. The control valve 15c can adjust the opening degree of the low-pressure passage 15a based on the pressure in the second suction chamber 27b.

In this compressor, a pipe leading to the evaporator is connected to the suction hole 330 shown in FIG. 1 , and a pipe leading to the condenser is connected to the discharge hole 230 . The condenser is connected to the evaporator through piping and an expansion valve. The compressor, evaporator, expansion valve, condenser, and the like constitute the refrigeration circuit of the vehicle air conditioner. In addition, illustration of an evaporator, an expansion valve, a condenser, and each piping is omitted.

In the compressor configured as described above, when the drive shaft 3 rotates, the swash plate 5 rotates, and the pistons 9 reciprocate in the first cylinder bore 21a and the second cylinder bore 23a. Therefore, the volume of the first compression chamber 21d and the second compression chamber 23d changes according to the stroke of the piston. Therefore, in this compressor, the suction process of sucking the suction refrigerant into the first compression chamber 21d and the second compression chamber 23d and compressing the suction refrigerant in the first compression chamber 21d and the second compression chamber 23d are repeated. A compression process, a discharge process in which the compressed intake refrigerant is discharged from the first compression chamber 21d and the second compression chamber 23d as the discharge refrigerant, and the like.

Among them, during the suction stroke, the suction refrigerant sucked from the evaporator into the swash plate chamber 33 through the suction hole 330 reaches the first suction chamber 27a via the first connection path 37a. Then, the suction refrigerant reaching the first suction chamber 27a is sucked into the first suction reed valve 391a by opening the first suction hole 390a due to the differential pressure between the first compression chamber 21d and the first suction chamber 27a. Compression chamber 21d. Similarly, the suction refrigerant sucked into the swash plate chamber 33 from the evaporator through the suction hole 330 reaches the second suction chamber 27b via the second connection path 37b. Then, the suction refrigerant reaching the second suction chamber 27b is sucked into the second suction hole 410a by opening the second suction reed valve 411a due to the differential pressure between the second compression chamber 23d and the second suction chamber 27b. Compression chamber 23d.

In addition, during the discharge stroke, the suction refrigerant compressed in the first compression chamber 21 d is discharged into the first discharge chamber 29 a as discharge refrigerant, and reaches the junction discharge chamber 231 through the first communication passage 18 . Similarly, the intake refrigerant compressed in the second compression chamber 23d is discharged to the second discharge chamber 29b as discharge refrigerant, and reaches the confluence discharge chamber 231 through the second communication path 20 . Then, the discharged refrigerant that has reached the merged discharge chamber 231 is discharged from the discharge hole 230 to the condenser.

Also, during the suction stroke and the like described above, the piston compressive force reducing the inclination angle of the swash plate 5 acts on the rotating body composed of the swash plate 5, the ring plate 45, the cantilever 49, and the first pin 47a. Furthermore, if the inclination angle of the swash plate 5 is changed, the displacement can be controlled by increasing or decreasing the stroke of the piston 9 .

Specifically, in the control mechanism 15, if the control valve 15c shown in FIG. The pressure inside is roughly equal. Therefore, by the piston compression force acting on the swash plate 5 , in the actuator 13 , the movable body 13 a moves toward the front of the swash plate chamber 33 as shown in FIG. 3 . Therefore, in this compressor, the movable body 13a approaches the boom 49, and the volume of the control pressure chamber 13c decreases.

As a result, the biasing force of the second return spring 44b is overcome, and the second side portion of the annular plate 45, that is, the second side portion of the swash plate 5, swings clockwise around the acting axis M3. In addition, the rear end of the boom 49 swings counterclockwise around the first swing axis M1 , and the front end of the boom 49 swings counterclockwise around the second swing axis M2 . The cantilever 49 thus approaches the flange 430 of the first support member 43a. Thus, the swash plate 5 swings with the action axis M3 as the action point and the first swing axis M1 as the fulcrum. Therefore, the inclination angle of the swash plate 5 relative to the rotation axis O of the drive shaft 3 is reduced, and the stroke of the piston 9 is reduced. In this compressor, therefore, the discharge capacity per revolution of the drive shaft 3 decreases. In addition, the inclination angle of the swash plate 5 shown in FIG. 3 is the minimum inclination angle of the compressor.

However, in this compressor, the centrifugal force acting on the weight portion 49 a is also applied to the swash plate 5 . Therefore, in this compressor, the swash plate 5 is easily displaced in a direction to decrease the inclination angle. In addition, since the movable body 13a moves forward of the swash plate chamber 33, the front end of the movable body 13a is positioned inside the weight portion 49a. Accordingly, in this compressor, when the inclination angle of the swash plate 5 decreases, approximately half of the front end of the movable body 13a is covered by the weight portion 49a.

In addition, since the inclination angle of the swash plate 5 is reduced, the annular plate 45 abuts against the rear end of the first return spring 44a. As a result, the first return spring 44a is elastically deformed, and the rear end of the first return spring 44a approaches the first support member 43a.

Here, in this compressor, the inclination angle of the swash plate 5 is reduced, and the stroke of the piston 9 is reduced, so that the top dead center position of the second head portion 9 b is separated from the second valve forming plate 41 . Therefore, in this compressor, the inclination angle of the swash plate 5 is close to zero degree, so that the compression operation is slightly performed in the first compression chamber 21d, and on the other hand, no compression operation is performed in the second compression chamber 23d.

On the other hand, when the control valve 15c shown in FIG. 2 decreases the opening of the low-pressure passage 15a, the pressure in the pressure adjustment chamber 31 increases, and the pressure in the control pressure chamber 13c increases. Therefore, against the piston compression force acting on the swash plate 5, in the actuator 13, the movable body 13a moves toward the rear of the swash plate chamber 33 as shown in FIG. Therefore, in this compressor, the movable body 13a moves away from the arm 49, and the volume of the control pressure chamber 13c increases.

As a result, the movable body 13 a pulls the lower part of the swash plate 5 toward the rear of the swash plate chamber 33 via the connection portion 132 at the working axis M3 . As a result, the portion on the second side of the swash plate 5 swings in the counterclockwise direction around the acting axis M3. In addition, the rear end of the cantilever 49 swings clockwise around the first swing axis M1 , and the front end of the cantilever 49 swings clockwise around the second swing axis M2 . The cantilever 49 is thus separated from the flange 430 of the first support member 43a. As a result, the swash plate 5 uses the action axis M3 and the first swing axis M1 as the action point and the fulcrum, respectively, and swings in opposite directions when the aforementioned inclination angle decreases. Therefore, by increasing the inclination angle of the swash plate 5 with respect to the rotation axis O of the drive shaft 3 , the stroke of the piston 9 is increased, thereby increasing the discharge capacity per rotation of the drive shaft 3 . In addition, the inclination angle of the swash plate 5 shown in FIG. 1 is the maximum inclination angle of the compressor.

Thus, in this compressor, the pressure in the control pressure chamber 13c increases, and the movable body 13a and the fixed body 13b move away from each other, thereby increasing the volume of the control pressure chamber 13c. On the other hand, as shown in FIG. 3, the pressure in the control pressure chamber 13c decreases, and the movable body 13a approaches the fixed body 13b, thereby reducing the volume of the control pressure chamber 13c. That is, in this compressor, as the volume of the control pressure chamber 13c increases, the discharge capacity per rotation of the drive shaft 3 increases. Conversely, as the volume of the control pressure chamber 13c decreases, the discharge capacity per revolution of the drive shaft 3 decreases.

In this compressor, the pressure adjustment chamber 31 formed in the rear casing 19 functions as a muffler for reducing pulsation of the discharged refrigerant and the sucked refrigerant. However, in this compressor, except when the discharge capacity is the minimum, the volume of the pressure adjustment chamber 31 is larger than the volume of the control pressure chamber 13c during the period from the minimum to the constant discharge capacity.

Moreover, in this compressor, the pressure adjustment chamber 31 is arrange|positioned between the 2nd suction chamber 27b, the 2nd discharge chamber 29b, and the control pressure chamber 13c. Therefore, in this compressor, when the discharge refrigerant in the second discharge chamber 29b flows into the control pressure chamber 13c via the pressure adjustment chamber 31, the discharge refrigerant reduces the pulsation in the pressure adjustment chamber 31 and flows into the control pressure chamber 13c. .

Also in this compressor, the pulsation of the suction refrigerant in the second suction chamber 27 b is reduced by the pressure adjustment chamber 31 . Therefore, in this compressor, when the inclination angle of the swash plate 5 is changed, the actuator 13 is less likely to be affected by the pulsation of the discharged refrigerant and the sucked refrigerant, and the inclination angle of the swash plate 5 can be stabilized.

Among them, since the pressure adjustment chamber 31 is formed to have a larger diameter than the first and second shaft holes 21b, 23b, and is formed to have a larger cross-sectional area than any of the low-pressure passage 15a, high-pressure passage 15b, shaft passage 3a, and passage 3b. , so it has enough volume. Therefore, in this compressor, the pressure adjustment chamber 31 properly functions as a muffler, and the pulsation of the discharged refrigerant and the sucked refrigerant can be sufficiently reduced.

Particularly in this compressor, as the inclination angle of the swash plate 5 approaches zero degrees, the volume of the control pressure chamber 13c decreases. In addition, in this compressor, since the inclination angle is close to zero degree, no compression operation is performed in the second compression chamber 23d. Therefore, since the inclination angle is close to zero, the influence of the pulsation of the discharged refrigerant and the sucked refrigerant tends to become significant in the actuator 13 . In this regard, in this compressor, since the pulsation of the discharge refrigerant etc. is reduced by the pressure adjustment chamber 31 as described above, even when the volume of the control pressure chamber 13c is small, that is, when the discharge capacity is small, In this case, the inclination angle of the swash plate 5 is also stable.

Therefore, the compressor of the first embodiment can operate with an appropriate discharge capacity.

(second embodiment)

As shown in FIG. 4, the compressor of the second embodiment includes: a casing 201, a drive shaft 203, a swash plate 205, a link mechanism 207, a plurality of pistons 209, a plurality of pairs of shoes 211a, 211b, an actuator 213 and The control mechanism 16 shown in FIG. 5 .

As shown in FIG. 4 , the housing 201 has: a front housing 217 located on the front side of the compressor, a rear housing 219 located on the rear side of the compressor, and a cylinder block located between the front housing 217 and the rear housing 219 221 and a valve forming plate 223 .

The front housing 217 has a front wall 217a extending in the vertical direction of the compressor on the front side, and a peripheral wall 217b integrated with the front wall 217a and extending from the front to the rear of the compressor. The front case 217 has a substantially cylindrical shape with a bottom formed by the front wall 217a and the peripheral wall 217b. Moreover, the swash plate chamber 225 is formed in the front case 217 by the said front wall 217a and the peripheral wall 217b.

A protrusion 217c protruding forward is formed on the front wall 217a. A shaft sealing device 227 is provided inside the protrusion 217c. In addition, a first shaft hole 217d extending in the front-rear direction of the compressor is formed in the protrusion 217c. A first slide bearing 229a is provided in the first shaft hole 217d.

A suction port 250 communicating with the swash plate chamber 225 is formed on the peripheral wall 217b. The swash plate chamber 225 is connected to an evaporator (not shown) through the suction port 250 .

A part of the control mechanism 16 is provided on the rear case 219 . In addition, a first pressure adjustment chamber 32 a , a suction chamber 34 , and a discharge chamber 36 are formed in the rear housing 219 . The first pressure adjustment chamber 32 a is located at the central portion of the rear case 219 . The discharge chamber 36 is located radially outside the rear housing 219 in an annular shape. In addition, the suction chamber 34 is formed in a ring shape between the first pressure adjustment chamber 32 a and the discharge chamber 36 in the rear housing 219 . The discharge chamber 36 is connected to a discharge hole (not shown). The rear case 219 also corresponds to the cover in the present invention.

In the cylinder block 221 , the same number of cylinder bores 221 a as the pistons 209 are formed at equal angular intervals along the circumferential direction. Each cylinder bore 221a communicates with the swash plate chamber 225 at its front end. In addition, the cylinder block 221 is formed with a stopper groove 221b that restricts the maximum opening degree of the suction reed valve 61a described later.

Moreover, the cylinder block 221 is provided with the 2nd shaft hole 221c penetrated, and this 2nd shaft hole 221c communicates with the swash plate chamber 225, and extends along the front-rear direction of a compressor. A second sliding bearing 229b is provided in the second shaft hole 221c. The first shaft hole 217d and the second shaft hole 221c also correspond to the shaft hole in the present invention.

In this compressor, the first pressure adjustment chamber 32a is formed to have a larger diameter than the first shaft hole 217d and the second shaft hole 221c. Thus, in this compressor, the cylinder block 221 and the rear housing 219 are joined via the valve forming plate 223, and the first pressure adjustment chamber 32a is in a state of covering the second shaft hole 221c.

In addition, a spring chamber 221d is formed in the cylinder block 221 . The spring chamber 221d is located between the swash plate chamber 225 and the second shaft hole 221c. A return spring 237 is arranged in the spring chamber 221d. The return spring 237 presses the swash plate 205 having the smallest inclination angle toward the front of the swash plate chamber 225 . In addition, a suction passage 239 communicating with the swash plate chamber 225 is formed in the cylinder block 221 .

In this compressor, the swash plate chamber 225 and the suction chamber 34 communicate with each other through the suction passage 239 . Therefore, the pressure in the suction chamber 34 is substantially equal to the pressure in the swash plate chamber 225 . Furthermore, since the low-pressure suction refrigerant flowing through the evaporator through the suction port 250 flows into the swash plate chamber 225 , the pressures in the swash plate chamber 225 and the suction chamber 34 are lower than the pressure in the discharge chamber 36 .

The valve forming plate 223 is disposed between the rear housing 219 and the cylinder block 221 . The valve forming plate 223 is composed of a valve plate 60 , a suction valve plate 61 , a discharge valve plate 63 , and a baffle plate 65 .

The same number of suction holes 60 a as the cylinder bores 221 a are formed in the valve plate 60 , the discharge valve plate 63 , and the baffle plate 65 . In addition, the same number of discharge holes 60 b as the cylinder bores 221 a are formed in the valve plate 60 and the suction valve plate 61 . Each cylinder bore 221a communicates with the suction chamber 34 through each suction hole 60a, and communicates with the discharge chamber 36 through each discharge hole 60b. In addition, a first communication hole 60 c and a second communication hole 60 d are formed in the valve plate 60 , the suction valve plate 61 , the discharge valve plate 63 , and the baffle plate 65 . The suction chamber 34 and the suction passage 239 communicate with each other through the first communication hole 60c.

The suction valve plate 61 is provided on the front surface of the valve plate 60 . The suction valve plate 61 is formed with a plurality of suction reed valves 61 a which can open and close the respective suction holes 60 a by elastic deformation. In addition, a discharge valve plate 63 is provided on the rear surface of the valve plate 60 . The discharge valve plate 63 is formed with a plurality of discharge reed valves 63 a that can open and close the respective discharge holes 60 b through elastic deformation. The baffle 65 is provided on the rear surface of the discharge valve plate 63 . The damper 65 limits the maximum opening of the discharge reed valve 63a.

The drive shaft 203 is inserted toward the rear of the housing 201 from the protrusion 217c. The front portion of the drive shaft 203 is inserted through the shaft seal device 227 in the protrusion 217c, and is pivotally supported by the first slide bearing 229a in the first shaft hole 217d. In addition, the rear portion of the drive shaft 203 is pivotally supported by the second slide bearing 229b in the second shaft hole 221c. In this way, the drive shaft 203 is supported by the casing 201 so as to be rotatable around the rotation axis O. As shown in FIG. Furthermore, a second pressure adjustment chamber 32 b is defined between the second shaft hole 221 c and the rear end of the drive shaft 203 . The second pressure adjustment chamber 32b communicates with the first pressure adjustment chamber 32a through the second communication hole 60d. The pressure adjustment chamber 32 is formed by the said 1st pressure adjustment chamber 32a and the 2nd pressure adjustment chamber 32b.

In addition, seal rings 249 a and 249 b are provided at the rear end of the drive shaft 3 . The pressure adjustment chamber 32 is sealed by the sealing rings 249a and 249b, so that the swash plate chamber 225 and the pressure adjustment chamber 32 are not communicated with each other.

A link mechanism 207 , a swash plate 205 , and an actuator 213 are attached to the drive shaft 203 . The link mechanism 207 is configured to include a suspension plate 251 , a pair of suspension arms 253 formed on the suspension plate 251 , and a pair of swash plate arms 205 e formed on the swash plate 205 . In addition, in this figure, only one side is shown in each of the cantilever arm 253 and the swash plate arm 205e. The same applies to Fig. 6 .

As shown in FIG. 4 , the hanging plate 251 is formed in a substantially annular shape. The suspension plate 251 is press-fitted into the drive shaft 203 and can rotate integrally with the drive shaft 203 . The hanging plate 251 is located on the front side in the swash plate chamber 225 and is arranged in front of the swash plate 205 . In addition, a thrust bearing 255 is provided between the suspension plate 251 and the front wall 217a.

A cylindrical cylinder chamber 251 a extending in the front-rear direction of the suspension plate 251 is recessed in the suspension plate 251 . The cylinder chamber 251 a extends from the rear end surface of the suspension plate 251 to a position inside the suspension plate 251 that becomes the inner side of the thrust bearing 255 .

Each suspension arm 253 extends rearward from the suspension plate 251 . In addition, sliding surfaces 251b are formed on the suspension plate 251 and at positions between the suspension arms 253 .

The swash plate 205 has an annular flat plate shape and has a front surface 205a and a rear surface 205b. A weight portion 205c protruding forward of the swash plate 205 is formed on the front surface 205a. The weight portion 205c contacts the suspension plate 251 when the inclination angle of the swash plate 205 is maximum. In addition, an insertion hole 205 d is formed at the center of the swash plate 205 . The drive shaft 203 is inserted through the insertion hole 205d.

Each swash plate arm 205e is formed on the front surface 205a. Each swash plate arm 205e extends forward from the front surface 205a. In addition, in the swash plate 205, a substantially hemispherical convex portion 205g is protrudingly provided on the front surface 205a, and is integrated with the front surface 205a. This convex part 205g is located between each swash plate arm 5e.

In this compressor, the suspension plate 251 and the swash plate 205 are connected to each other by inserting the respective swash plate arms 205e between the respective suspension arms 253 . Thus, the swash plate 205 can rotate in the swash plate chamber 225 together with the suspension plate 251 . In this manner, by connecting the suspension plate 251 and the swash plate 205 to each other, the tip portions of the swash plate arms 205e come into contact with the sliding surfaces 251b, respectively. Then, each swash plate arm 205e slides on the sliding surface 251b, so that the swash plate 205 can substantially maintain the top dead center position T with respect to the inclination angle of the swash plate 205 with respect to the direction perpendicular to the rotation axis O. The maximum tilt angle shown, changes to the minimum tilt angle in Figure 6.

As shown in FIG. 4, the actuator 213 is comprised including the suspension plate 251, the movable body 213a, and the control pressure chamber 213b. The hanging plate 251 constitutes the link mechanism 207 as described above, and also functions as a fixed body in the present invention.

The movable body 213 a is inserted through the drive shaft 203 , is in sliding contact with the drive shaft 203 , and is movable in a direction along the rotation axis O. As shown in FIG. The movable body 213 a has a cylindrical shape coaxial with the drive shaft 203 and has a smaller diameter than the thrust bearing 255 . The movable body 213a is formed to expand in diameter from the rear side toward the front side.

Moreover, the action part 234 is integrally formed in the rear end of the movable body 213a. The acting portion 234 extends vertically from the rotation axis O toward the top dead center position T of the swash plate 205, and is in point contact with the convex portion 205g. Thereby, the movable body 213 a can rotate integrally with the suspension plate 251 and the swash plate 205 .

The movable body 213a can be fitted into the suspension plate 251 by entering the front end side of itself into the cylinder chamber 251a. Then, when the front end of the movable body 213a enters the innermost state of the cylinder chamber 251a, the front end of the movable body 213a reaches a position inside the thrust bearing 255 within the cylinder chamber 251a.

The control pressure chamber 213 b is formed between the front portion of the movable body 213 a and the cylinder chamber 251 a and the drive shaft 203 . The control pressure chamber 213 b is partitioned from the swash plate chamber 225 by the movable body 213 , the suspension plate 251 , and the drive shaft 203 , and is partitioned from the pressure adjustment chamber 32 .

Formed in the drive shaft 203 are: an axial path 203a extending from the rear end of the drive shaft 203 toward the front end and in a direction along the rotation axis O; The path 203b opened on the outer peripheral surface of the The rear end of the shaft path 203 a is opened in the pressure adjustment chamber 32 . On the other hand, the path 203b is opened at the control pressure chamber 213b. The pressure adjustment chamber 32 and the control pressure chamber 213b communicate with each other through the above-mentioned shaft path 203a and path path 203b.

In addition, like the compressor of the first embodiment, the drive shaft 203 is connected to an unshown pulley or an electromagnetic clutch through a threaded portion 203e formed at the front end.

Each piston 209 is accommodated in the corresponding cylinder bore 221a, respectively, and can reciprocate in the corresponding cylinder bore 221a. Each piston 209 and the valve forming plate 223 define a compression chamber 257 in the corresponding cylinder bore 221a.

In addition, each piston 209 is recessed with an engaging portion 209a. Hemispherical shoes 211a, 211b are respectively provided in the engaging portion 209a. Each shoe 211a, 211b converts the rotation of the swash plate 205 into the reciprocating motion of each piston 209 . Each of the above-mentioned shoes 211a, 211b also corresponds to the switching mechanism in the present invention. In this way, each piston 209 can reciprocate within the cylinder bore 221 a with a stroke corresponding to the inclination angle of the swash plate 205 .

As shown in FIG. 5 , the control mechanism 16 has a low-pressure passage 16a, a high-pressure passage 16b, a control valve 16c, an orifice 16d, a shaft passage 203a, and a passage 203b. The shaft path 203a and the path path 203b correspond to the transformer path in the present invention. In addition, the control passage in the present invention is formed by the low-pressure passage 16a, the high-pressure passage 16b, the shaft passage 203a, and the passage 203b.

The low-pressure passage 16 a is connected to the pressure adjustment chamber 32 and the suction chamber 34 . The control pressure chamber 213b, the pressure adjustment chamber 32, and the suction chamber 34 are communicated with each other through the low-pressure passage 16a, the shaft passage 203a, and the passage 203b. The high-pressure passage 16 b is connected to the pressure adjustment chamber 32 and the discharge chamber 36 . The discharged refrigerant in the discharge chamber 36 flows through the high-pressure passage 16b. The control pressure chamber 213b, the pressure adjustment chamber 32 and the discharge chamber 36 communicate with each other through the high-pressure passage 16b, the shaft passage 203a, and the passage 203b. In addition, an orifice 16d is provided in the high-pressure passage 16b.

Furthermore, by connecting the suction chamber 34, the discharge chamber 36, and the pressure adjustment chamber 32 to the control pressure chamber 213b in this way, the pressure adjustment chamber 32 is located between the suction chamber 34, the discharge chamber 36, and the control pressure chamber 213b. In addition, the pressure adjustment chamber 32 is formed as a space having a cross-sectional area larger than any one of the low-pressure passage 16a, the high-pressure passage 16b, the axial passage 203a, and the path 203b.

The control valve 16c is provided in the low-pressure passage 16a. The control valve 16c can adjust the opening degree of the low-pressure passage 16a based on the pressure in the suction chamber 34 .

In this compressor, a pipe leading to the evaporator is connected to the suction port 250 shown in FIG. 4 , and a pipe leading to the condenser is connected to the discharge hole. In this way, like the compressor of the first embodiment, this compressor also constitutes the refrigeration circuit of the vehicle air conditioner together with the evaporator, the expansion valve, the condenser, and the like.

In the compressor configured as described above, when the drive shaft 203 rotates, the swash plate 205 rotates, and each piston 209 reciprocates in each cylinder bore 221a. Therefore, the volume of the compression chamber 257 changes according to the stroke of the piston. Therefore, the suction refrigerant sucked into the swash plate chamber 225 from the evaporator through the suction port 250 is compressed in the compression chamber 257 through the suction chamber 34 from the suction passage 239 . Then, the suction refrigerant compressed in the compression chamber 257 is discharged to the discharge chamber 36 as a discharge refrigerant, and is also discharged to the condenser through the discharge hole.

In addition, similarly to the compressor of the first embodiment, in this compressor, the stroke of the piston 209 is increased or decreased by changing the inclination angle of the swash plate 205, thereby enabling capacity control.

Specifically, in the control mechanism 16, if the control valve 16c shown in FIG. The pressure is roughly equal. Therefore, by the piston compression force acting on the swash plate 205, as shown in FIG. 4, in the actuator 213, the movable body 213a moves from the swash plate 205 toward The suspension plate 251 slides, thereby reducing the volume of the control pressure chamber 213b. Furthermore, the front end of the movable body 213a enters into the cylinder chamber 251a.

At the same time, in this compressor, each swash plate arm 205e slides on the sliding surface 251b so as to be separated from the rotation axis O. As shown in FIG. Therefore, in the swash plate 205, the top dead center position T is substantially maintained, and the portion on the bottom dead center side swings clockwise. Thus, in this compressor, the inclination angle of the swash plate 205 with respect to the rotation axis O of the drive shaft 203 increases. Accordingly, in this compressor, the stroke of the piston 209 is increased, and the discharge capacity per rotation of the drive shaft 203 is increased. In addition, the inclination angle of the swash plate 205 shown in FIG. 4 is the maximum inclination angle of the compressor.

On the other hand, when the control valve 16c shown in FIG. 5 decreases the opening of the low-pressure passage 16a, the pressure in the pressure adjustment chamber 32 increases, and the pressure in the control pressure chamber 213b increases. Therefore, as shown in FIG. 6, since the movable body 213a moves away from the suspension plate 251 and slides in the direction along the rotation axis O toward the swash plate 205 in the cylinder chamber 251a, in the actuator 213, the control The volume of the pressure chamber 213b increases.

Accordingly, in this compressor, the action portion 234 presses the convex portion 205g toward the rear of the swash plate chamber 225 . Therefore, each swash plate arm 205e slides on the sliding surface 251b so as to approach the rotation axis O. As shown in FIG. As a result, the top dead center position T of the swash plate 205 is substantially maintained, and the portion on the bottom dead center side swings in the counterclockwise direction. Thus, in this compressor, the inclination angle of the swash plate 5 with respect to the rotation axis O of the drive shaft 203 is reduced. Accordingly, in this compressor, the stroke of the piston 209 decreases, and the discharge capacity per rotation of the drive shaft 203 decreases. In addition, the inclination angle of the swash plate 205 shown in FIG. 6 is the minimum inclination angle of the compressor.

In this compressor, like the compressor of the first embodiment, the pressure adjustment chamber 32 also functions as a muffler that reduces the pulsation of the discharged refrigerant and the sucked refrigerant. However, in this compressor, except when the discharge capacity is the maximum, the volume of the pressure adjustment chamber 32 is larger than the volume of the control pressure chamber 213b when the discharge capacity is from the maximum to a constant size.

Moreover, in this compressor, the pressure adjustment chamber 32 is arrange|positioned between the suction chamber 34 and the discharge chamber 36, and the control pressure chamber 213b. Therefore, in this compressor, when the discharge refrigerant in the discharge chamber 36 flows into the control pressure chamber 213b via the pressure adjustment chamber 32, the discharge refrigerant reduces the pulsation in the pressure adjustment chamber 32 and flows into the control pressure chamber 213b. In addition, in this compressor, the pulsation of the suction refrigerant in the suction chamber 34 is also reduced by the pressure adjustment chamber 32 . In this compressor, even when the inclination angle of the swash plate 205 is changed, the actuator 213 is hardly affected by the pulsation of the refrigerant discharged and sucked in, and the inclination angle of the swash plate 205 can be stabilized.

In addition, in this compressor, the pressure adjustment chamber 32 is formed by the first pressure adjustment chamber 32a and the second pressure adjustment chamber 32b, and the first pressure adjustment chamber 32a is formed to be smaller in diameter than the first shaft hole 217d and the second shaft hole 221c. Big diameter. In addition, the pressure adjustment chamber 32 is formed to have a larger passage cross-sectional area than any of the low-pressure passage 16a, the high-pressure passage 16b, the shaft passage 203a, and the path passage 203b. Therefore, also in this compressor, the pressure adjustment chamber 32 has a sufficient volume. Accordingly, even in this compressor, the pulsation of the discharged refrigerant and the sucked refrigerant can be sufficiently reduced by the pressure adjustment chamber 32 .

Especially in this compressor, as the inclination angle of the swash plate 205 increases, the volume of the control pressure chamber 213b decreases, and the inclination angle of the swash plate 205 is the largest, that is, when the discharge capacity is the largest, the volume of the control pressure chamber 213b minimum. Therefore, in this compressor, contrary to the compressor of the first embodiment, when the discharge capacity changes from the maximum state to decrease the discharge capacity, in the actuator 213, the refrigerant is discharged and sucked in. The effects of pulsation tend to become significant. However, even in this compressor, the pulsation of the discharged refrigerant can be reduced by the pressure adjustment chamber 32 as described above, so even when the discharge capacity changes from the maximum state, the inclination of the swash plate 205 Angles are also stable. Other functions of this compressor are the same as those of the compressor of the first embodiment.

As mentioned above, although the present invention has been described with reference to the first and second embodiments, the present invention is not limited to the above-mentioned first and second embodiments, and it is of course possible to appropriately change and apply it within a range not departing from the gist thereof. .

For example, in the control mechanism 15 of the compressor of the first embodiment, the control valve 15c may be provided in the high-pressure passage 15b, and the orifice 15d may be provided in the low-pressure passage 15a. In this case, the opening degree of the high-pressure passage 15b can be adjusted by the control valve 15c. As a result, the high pressure in the second discharge chamber 29b can be used to rapidly increase the pressure in the control pressure chamber 13c, thereby enabling rapid reduction in the compression capacity. The same applies to the control mechanism 16 of the compressor of the second embodiment.

In addition, in the compressor of the second embodiment, the suspension plate 251 and the swash plate 205 may be connected by connecting each swash plate arm 205e to the suspension arm 253 so as to be swingable by a connection pin or the like.

In addition, in the compressor of the first embodiment, although the pressure adjustment chamber 31 is formed only in the rear housing 19, it is not limited thereto, and may be formed in the rear housing 19 and the second cylinder block 23, or may be formed only in the rear housing 19. Formed in the second cylinder block 23 .

In addition, in the compressor of the second embodiment, the pressure adjustment chamber 32 may be constituted only by the first pressure adjustment chamber 32a formed in the rear casing 219, or may be formed only by the second pressure adjustment chamber 32b formed in the cylinder block 221. constitute.

Claims (5)

1. A variable-capacity swash plate compressor, characterized in that it has: a housing formed with a suction chamber, a discharge chamber, a swash plate chamber and a cylinder bore; a drive shaft rotatably supported on the housing; a swash plate rotatable within the swash plate chamber by rotation of the drive shaft; a link mechanism provided between the drive shaft and the swash plate, allowing a change in the inclination angle of the swash plate with respect to a direction orthogonal to the rotation axis center of the drive shaft; a piston housed in the cylinder bore capable of reciprocating movement; a conversion mechanism, which, by virtue of the rotation of the swash plate, causes the piston to reciprocate in the cylinder bore at a stroke corresponding to the inclination angle of the swash plate; an actuator capable of changing the inclination angle of the swash plate; and a control mechanism which controls the actuator, A pressure adjustment chamber is formed in the housing, The actuator has: a fixed body fixed to the drive shaft within the swash plate chamber; a movable body, which is provided on the drive shaft and moves in a direction along the rotation axis of the drive shaft, capable of changing the inclination angle of the swash plate; and a control pressure chamber, which is divided by the fixed body and the movable body, changes its volume by the pressure of the refrigerant in the discharge chamber to move the movable body, The control mechanism has: a control passage that communicates the discharge chamber, the pressure adjustment chamber, and the control pressure chamber; and a control valve that adjusts the opening degree of the control passage to change the pressure in the control pressure chamber in such a manner that the movable body can be moved, the refrigerant in the discharge chamber flows into the control pressure chamber through the pressure adjustment chamber, The pressure adjustment chamber functions as a muffler that reduces pulsation of the refrigerant, The housing has: a cylinder block formed with the cylinder bore and formed with a shaft hole through which the drive shaft is inserted; and a cover in which the suction chamber and the discharge chamber are formed, The pressure adjustment chamber is formed in at least one of the cylinder block and the head, The pressure adjustment chamber is formed in the cover radially inward of the suction chamber and the discharge chamber so as to cover the shaft hole. 2. The variable capacity swash plate compressor according to claim 1, characterized in that: The pressure adjustment chamber is a space having a cross-sectional area larger than that of the control passage. 3. The capacity variable swash plate compressor according to claim 1 or 2, characterized in that, The pressure adjustment chamber is disposed on the rear end side of the drive shaft, At least a portion of the control passage is formed within the drive shaft. 4. The variable capacity swash plate compressor according to claim 1 or 2, characterized in that, said suction chamber and/or said swash plate chamber is a low pressure chamber, The control path has: a high-pressure passage communicating the discharge chamber with the pressure adjustment chamber; a low-pressure passage communicating the low-pressure chamber with the pressure adjustment chamber; and A variable pressure passage is formed in the drive shaft and communicates the pressure adjustment chamber with the control pressure chamber. 5. The variable capacity swash plate compressor according to claim 4, characterized in that: The control valve is arranged in the low-pressure passage, An orifice is provided in the high-pressure passage.